SB2021090127 - Red Hat Enterprise Linux 7 update for kernel
Published: September 1, 2021 Updated: February 8, 2024
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Race condition (CVE-ID: CVE-2021-32399)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition for removal of the HCI controller within net/bluetooth/hci_request.c in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
2) Buffer overflow (CVE-ID: CVE-2021-29650)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error within the netfilter subsystem in net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h. A local user can trigger memory corruption upon the assignment of a new table value and cause denial of service.
3) Out-of-bounds write (CVE-ID: CVE-2021-22555)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error when processing untrusted input in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.
4) Missing Authorization (CVE-ID: CVE-2020-27777)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to the way RTAS handles memory accesses in userspace to kernel communication. On a locked down (usually due to Secure Boot) guest system running on top of PowerVM or KVM hypervisors (pseries platform) a root like user could use this flaw to further increase their privileges to that of a running kernel.
5) Command Injection (CVE-ID: CVE-2021-29154)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to incorrect computation of branch displacements within the BPF JIT compilers in the Linux kernel in arch/x86/net/bpf_jit_comp.c and arch/x86/net/bpf_jit_comp32.c. A local user can inject and execute arbitrary commands with elevated privileges.
Remediation
Install update from vendor's website.